RFR: 8358537: (bf) JavaNioAccess::getBufferAddress bypasses direct buffer MemorySession state check

[Brian Burkhalter]

Add package-scope `long java.nio.Buffer::address()` to simply return the value of the `address` instance variable; use this method in `JavaNioAccess::getBufferAddress`.

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Commit messages:
 - 8358537: (bf) JavaNioAccess::getBufferAddress bypasses direct buffer MemorySession state check

Changes: https://git.openjdk.org/jdk/pull/25631/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25631&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8358537
  Stats: 16 lines in 3 files changed: 11 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/25631.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25631/head:pull/25631

PR: https://git.openjdk.org/jdk/pull/25631